AU-888 no sound

[RAOF]

Hi,

I bought a AU-888 in ebay, supposedly working.

It arrived, I connected my cd player in AUX and no sound.

It turns ON, I have a red light but no sound.

The fuses in the back are ok.

Any idea where to look?


Thank you

 

[Robisme]

Your speakers are connected at both ends?

Are you using C speaker outputs? Needs pre/main jumpers in place if so.

Is the tape monitor switch set to source?

Operate all the controls a few times and see if you get sound.

Open it up and see if any boards came loose during shipping.

Rob

 

[slimecity]

"No sound" is weird - agree with Robisme - switch the speaker selector to "A" speaker outputs and make sure it isn't switched to "C" speaker outputs, connect speakers to "A" speaker terminals at the back and let us know how you get on......

 

[RAOF]

Replying to the questions and a "interesting" update:
- speakers are connected in both ends. And they are working. Just disconnected them from a "modern" Onkyo TX-NR818.
- tried both A and B outputs. Not tried C outputs. Pre/main jumpers are in place.
- tape monitor is set to source.

I've already tried to operate controls but no change. No time available yet to open it.

Now the update:
- today I used some headphones and I get sound.
- moving balance control all to the right I get sound in right. All to the left I get no sound in left and a little sound in right.

 

[petehall347]

maybe its time to get in touch with the seller with a view to sending it back .

 

[krazybones]

Replying to the questions and a "interesting" update:
- speakers are connected in both ends. And they are working. Just disconnected them from a "modern" Onkyo TX-NR818.
- tried both A and B outputs. Not tried C outputs. Pre/main jumpers are in place.
- tape monitor is set to source.

I've already tried to operate controls but no change. No time available yet to open it.

Now the update:
- today I used some headphones and I get sound.
- moving balance control all to the right I get sound in right. All to the left I get no sound in left and a little sound in right.

I have an AU-555a and I had similar issues you speak of. Ended up being a dirty Selector Switch. Clean all contacts solved all my issues.

 

[rasenthiran]

Since the headphone has sound, most likely one of the controls in not set at the correct position, which is preventing the output to speaker. Rob advice is correct.

 

[mroboto]

Oups, i misread.

Was going to ask about Pre-Out Main-In jumpers...

 

[RAOF]

Today, I tried again with headphones.

I have my speakers connect in output A.

Spaeker control in position:
- Off: sound in headphones
- A: no sound in headphones
- B: sound in headphones

 

[Robisme]

Clean all the controls.

Rob

 

[mroboto]

Yes, clean all contacts, even the relay contacts.

Remove the relay

Open is box taking attention to not broke the coils leads on both sides,

Clean the contacts with a toothbrush and Brasso metal polish.

 

[slimecity]

There is no relay in the 888. The circuit is pretty simple. As well as cleaning the controls I would look at (make sure the amplifier is OFF!!!) opening it up, pulling out all the boards (both poweramp boards and all 4 x preamp boards) clean the contacts with contact cleaner, make sure contact with the boards and the pins is good, try again......Be VERY careful in removing the power amp boards as you first want to very carefully pull the heatsink-mounted metal transistor from its mounting - if you break these leads, replacements are very hard to find (I speak from experience!) let us know how u get on.

 

[RAOF]

Today I open it... and:
- the 2 fuses from the right side of the picture are not ok. As I don't have any at home to replace then, I must wait until Monday to try to find replacements. Can't wait to try it to see if the problem was only the fuses.

I think it was not too dirty. But I give it a clean with my compressor and used a contact cleaner in all the switches and controls.

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[petehall347]

fuses blow for a reason . maybe the output devices have shorted .or the power supply is bad .
first be sure the voltage selector is correctly set for your country .

 

[slimecity]

Yep - replace the fuses with the correct value first. From memory one on each side is in the bias-setting circuit, so with the blown your poweramp wont run at all. After replacing the fuses, powerup the amp ONLY using a dim bulb tester in series with the powersupply. there is info on this site on how to make one (carefully!) You will need to find & download the service manual and calibrate the amp once it is powered up using the setup procedure in the manual. There may be a reason as petehall says for the blowing fuses, chances are in this amp the bias may have been set - or drifted - too high, taking out the fuse. once this is done u will need to find the service manual and set it up again - using the calibration (DC offset and bias) procedure in the manual.

 

[RAOF]

Hi everyone,

Just to let you know that, after replacing the fuses and after a Deox treatment, the AU-888 has returned to life.

And what a life!!!!

The sound is FANTASTIC!!!!

Diana Krall voice never sounded so good!

The source is a Grunding Fine Arts CD-903 modified with a TSA1541-S1 single crown.